/*
This file is part of CanFestival, a library implementing CanOpen Stack.

CanFestival Copyright (C): Edouard TISSERANT and Francis DUPIN
CanFestival Win32 port Copyright (C) 2007 Leonid Tochinski, ChattenAssociates, Inc.

See COPYING file for copyrights details.

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

// thread safe que
#ifndef __async_access_que_h__
#define __async_access_que_h__

#include <deque>
#include "AutoReleaseCS.h"

template<typename type>
class async_access_que
{
public:
    async_access_que()
    {
        ::InitializeCriticalSection(&m_cs);
        m_newObject = CreateEvent(NULL, FALSE, FALSE, NULL);
        m_stop = CreateEvent(NULL, FALSE, FALSE, NULL);
        m_stopped = CreateEvent(NULL, FALSE, FALSE, NULL);
        m_commands[0] = m_newObject;
        m_commands[1] = m_stop;
    }
    ~async_access_que()
    {
        SignalObjectAndWait(m_stop, m_stopped, 500, FALSE);
        ::DeleteCriticalSection(&m_cs);
        CloseHandle(m_stop);
        CloseHandle(m_stopped);
        CloseHandle(m_newObject);
    }

    void append(const type& data)
    {
        AutoReleaseCS acs(m_cs);
        m_data.push_back(data);
        SetEvent(m_newObject);
    }

    bool extract_top(type& data)
    {
        bool empty = true;
        {
            AutoReleaseCS acs(m_cs);
            empty = m_data.empty();
        }
        if (empty)
        {
            DWORD objectIndex;
            do
            {
                objectIndex = WaitForMultipleObjects(sizeof(m_commands) / sizeof(&(m_commands[0])), m_commands, FALSE, INFINITE);
                if (objectIndex - WAIT_OBJECT_0 == 1)   //m_stop
                {
                    SetEvent(m_stopped);
                    return false; //This will exit the canReceive-loop
                }
            } while (objectIndex - WAIT_OBJECT_0 != 0);
        }
        {
            AutoReleaseCS acs(m_cs);
            if (m_data.empty())
            {
                return false; //This will exit the canReceive-loop
            }
            data = m_data.front();
            m_data.pop_front();
            ResetEvent(m_newObject);
            return true;
        }
    }

    void clear()
    {
        AutoReleaseCS acs(m_cs);
        m_data.clear();
    }

protected:
    std::deque<type> m_data;
    CRITICAL_SECTION m_cs;

    HANDLE m_newObject;
    HANDLE m_stop;
    HANDLE m_stopped;
    HANDLE m_commands[2];
};
#endif //__async_access_que_h__